Field of the Invention
The present invention relates to a printing apparatus and method for carrying out printing by using a rolled continuous sheet.
Description of the Related Art
For a great deal of printing, for example, a laboratory print, a rolled continuous sheet is used. There is a printing apparatus configured such that a user sets a rolled continuous sheet, and the printing apparatus feeds the continuous sheet, carries out printing, cuts the continuous sheet by a cutter, and discharges the cut sheet to a sorter.
In an ink jet type printing head, a nozzle having a low frequency in use may be defective in an ink discharge due to an ink clogging or the like. In order to prevent the non-discharging nozzle from being generated, periodical head maintenance is necessary. Even in the case where a plurality of images are printed in the continuous sheet one by one, it is desirable to execute a periodical head maintenance which forms a maintenance pattern in a sheet by discharging inks from all the nozzles per predetermined number of image printing.
In a printing apparatus disclosed in Japanese Patent Laid-Open No. 2011-240492, a non-discharging monitoring pattern and a preliminary discharging pattern for the head maintenance are printed between pages in which images are printed. Hereinafter, kinds of printing except the image designated by the user, for example, the preliminary discharging pattern, the non-discharging monitoring pattern and a cut mark pattern are collectively called as a maintenance pattern.
In an apparatus which prints a plurality of images on a continuous sheet and discharges the continuous sheet after cutting per each image, the following problem is generated in the case where the sheet is clogged due to some reason. In the present specification, sheet clogging in the apparatus and a sheet clogging state are called as a paper jam.
In the case that the paper jam is generated at any one position from a paper supply position to a paper discharge position in the apparatus, it is necessary to stop a whole sheet feeding. Then, cut sheet pieces (cut sheets) are intermittently left in a feed path of the sheet. Although it is necessary for a user to remove the left sheet pieces, there is a case that the sheet piece is left even after the user thought he/she had removed all the sheet pieces. This is because the sheet piece exists not only on the feed path, but the sheet piece is also frequently clogged in an unexpected portion. In the case where a recovering operation is carried out under such the state, not only an error is regenerated, but also a further severe paper jam may be generated.
In order to securely remove all the sheet pieces, it is effective for the user to recognize how many sheet pieces are left in the feed path.